WO2010076491A1

WO2010076491A1 - Method and device for applying a fluid to the bottoms of thermoplastic containers, in particular for cooling the hot bottoms of thermoplastic containers after moulding

Info

Publication number: WO2010076491A1
Application number: PCT/FR2009/052551
Authority: WO
Inventors: Bernard Plantamura
Original assignee: Sidel Participations
Priority date: 2008-12-17
Filing date: 2009-12-15
Publication date: 2010-07-08
Also published as: FR2939708A1; FR2939708B1

Abstract

The invention relates to the application of a liquid to the bottom (2) of a thermoplastic container (1) moved such that the bottom follows a path (T) with a constant slope above a tank (4) containing the liquid (3); at one end of the tank, at least one jet (5) of liquid is sprayed upwards at an angle, forming a wall (6) of liquid capable of raising the level (N) of the liquid in the tank; a leakage (F) of liquid is created in the tank with a flow rate equal to the flow rate of the jet; and the path of the bottom is such that the bottom crosses the wall (6) of liquid and, for a predetermined time, passes through the liquid held in the tank. The invention can be used for cooling the hot bottoms of containers after blow moulding.

Description

METHOD AND INSTALLATION FOR APPLYING A FLUID

ON FUNDS OF THERMOPLASTIC CONTAINERS,

NOTABLY FOR THE COOLING OF HOT FUNDS

THERMOPLASTIC CONTAINERS RELEASING FROM MOLDING

The present invention relates generally to the field of manufacturing thermoplastic containers, such as PET, by blowing or stretch-blow molding hot preforms into molds. The invention relates more particularly to the application of a liquid to the bottoms of thermoplastic containers, including, although not exclusively, for the cooling of the hot bottoms of thermoplastic containers coming out of a blow mold or stretch blow molding.

The bottom is the part of thermoplastic containers that is the most delicate to process and requires the most attention during the manufacturing process. Furthermore, the bottom is the portion of the containers which has, at least in part, the largest thickness (typically the thickness of the bottom, at least locally, may be between the minimum and twenty times the thickness of the container body wall). Therefore, the bottom accumulates, during the heating step conducted prior to the molding step, a large amount of heat that is still substantially present at the time the finished container is removed from the mold.

However, the hot bottom is mechanically very fragile, because the thermoplastic material still very hot can be deformed if only by the action of its own weight and / or residual stresses related to the blowing process. But the respect of a perfect form of the bottom of the container ensures the stability of the container placed on a flat support, and any deformation of the bottom compromises this stability and makes the container unusable commercially. It is therefore of great importance that the material constituting at least the thick zone of the bottom is cooled as quickly as possible below the glass transition temperature (Tg), as soon as the finished container is out of the mold, to freeze the structure of the thermoplastic material.

Until now, the cooling of the bottoms of the outgoing molding containers could be obtained by natural cooling in the ambient atmosphere on the path to the next station (for example a filling machine) when this path was of sufficient duration ( for example a few tens of seconds).

In some installations, the projection of a gaseous fluid (generally air) or a liquid (generally water) sprayed in the form of a mist, possibly cooled, has also been possible. on the bottoms of containers being scrolled at the exit of the molding installation to accelerate the cooling of funds. However, this type of layout complicates the structural design of installations that are already heavily encumbered and increases manufacturing and maintenance costs. In addition, the cooling fluid jets can generate pollution (moisture, appearance of germs, ...) of both the blowing installation and the final containers, as well as disturbances in neighboring parts of the installation. As a result, it is sought in practice to avoid such developments. Last but not least, the operators of thermoplastic container manufacturing facilities require ever-increasing operating speeds, and speeds of the order of 80,000 containers / hour are currently envisaged. In addition, the search for ever more compact installations for the sake of saving implantation area leads to bringing the various treatment stations closer, for example between the blowing installation and the filling installation that succeeds it. This results in a considerable shortening of the transit time of the containers (for example, the transfer time of the containers between the blowing installation and the filling installation could become of the order of a small number of seconds) . Under such conditions, it is no longer possible for the bottoms of the molded containers to be cooled under the conditions hitherto practiced.

Independently of what has just been exposed in connection with the cooling of hot bottoms of thermoplastic containers coming out of molding and which is of a general nature in the context of the manufacture of thermoplastic containers, it may also be required, for certain productions, the application of a liquid product on the bottom of thermoplastic containers not to lower the temperature as described above, but on the contrary to raise the temperature or to cause a change in the surface condition of the bottom of the containers . In at least some cases, a modification of the surface properties of the bottom of the containers may be obtained by the application of a suitable liquid on the external face of said bottom (for example: depositing a protective layer against in particular chemical aggressions; coloring of the outer surface of the backgrounds, in particular for decorative purposes; etc.).

The object of the invention is to provide means (process and installation) for applying a liquid to bottoms of containers, in particular but not exclusively for the purpose of rapidly cooling the bottoms of containers leaving the molding, and this in acceptable cost and space conditions in facilities with a very high rate of production and under technical conditions that do not cause any change or disruption in upstream and downstream processes. In particular, with regard to the high transfer speeds envisaged for the displacement of the containers, it is desired that the treatment applied to the bottoms of the containers may be carried out with continuous linear or curvilinear paths, in particular circular paths, without abrupt modification of the direction of rotation. displacement in particular vertically.

For these purposes, according to a first of its aspects, the invention provides a method for applying to the parade a liquid on the bottom of at least one thermoplastic container, in particular PET, driven in displacement so that its bottom follows a pre-established trajectory with a substantially constant slope passing over a reservoir containing said liquid, which process is characterized

in that at or at least one end of the reservoir situated under said bottom trajectory, at least one liquid jet inclined toward an opposite end of the reservoir and of substantially transverse extent to said reservoir is projecting upwards; path of the bottom so as to create at least one wall or portion of clean liquid wall to retain the liquid and to raise the level of the liquid retained inside the tank,

in that a liquid leak is created in said reservoir having a flow rate substantially equal to the flow rate of the liquid introduced by said jet of liquid, and

in that said bottom trajectory is positioned above the tank in such a way that the bottom of said at least one moving vessel is passed through said at least one liquid wall and through, for a predetermined period of time, the liquid that it holds in the tank.

Thanks to this arrangement, the liquid wall thus created is able to retain a certain volume of liquid in the tank, which leads to an elevation of the level of liquid in the tank above the static level normally provided by the solid walls defining the tank. This liquid wall can be traversed by the bottom of a container moved by transport means, so that said bottom can remain immersed in the reservoir liquid for a predetermined time.

Preferably, said liquid jet is inclined at an angle of between about 20 ° and 60 °, preferably about 40 °, so as to obtain a liquid wall that is stable despite the disturbances caused by the passage of container bottoms and which is able to oppose the hydrostatic pressure of the raised level liquid held in the tank. In one possible embodiment of the method of the invention, provision may be made to use at least one liquid wall located at or towards a single end of the tank and to move the at least one container of way that said trajectory followed by its bottom is inclined relative to the level of the liquid retained in the tank. In particular, it is possible to ensure that the at least one liquid wall is located on the side of the inlet of the tank: the bottom of the container firstly through this liquid wall to then continue its inclined race, which must then be ascending , within the liquid tank, then leave it before reaching the opposite wall of the tank. Conversely, it is also possible to ensure that said at least one liquid wall is located on the side of the outlet of the tank: the bottom of the container must then be approached from the surface of the liquid in the tank and then moved within said liquid with an inclined downward stroke, and finally out of the tank through the liquid wall.

However, it is preferred to use two liquid walls located respectively at or towards two opposite ends of the reservoir, so that said at least one container can be moved so that said trajectory followed by its bottom is substantially parallel to the liquid held in the tank. In other words, particularly interestingly, the bottom of the container can be moved horizontally through the superficial liquid layer of the reservoir.

Where necessary, a significant increase in the level of liquid in the central part of the tank can be obtained by providing at least one end of the tank with several successive liquid walls. For the practical implementation of the method according to the invention, it is possible to use various complementary solutions.

In particular, it is possible to regulate at least one characteristic, especially the temperature, of the liquid sprayed by the at least one nozzle.

It is also possible to recover the liquid escaping by said leakage and to ensure that the recovered liquid is treated before being returned to said at least one nozzle.

It is also possible to provide that after the application of the liquid on the bottom of the container, at least part of the surface of said bottom is dried.

The means proposed by the invention make it possible to treat the bottoms of containers by adding a liquid to said bottoms under conditions compatible with the high rates currently required by the manufacturers and / or packers. Thus, it can be envisaged to quickly change the bottom temperature of at least one container of thermoplastic material, providing for this purpose that the liquid is then a coolant liquid in contact with which said bottom is maintained for a predetermined period.

This aspect of the process according to the invention seems to find a particularly interesting, although not exclusive, application for rapidly cooling the hot bottom of at least one thermoplastic container coming out of a blow molding or drawing mold. blowing, which process is characterized in that the liquid used is a coolant at a temperature below that of said bottom, in contact with which said bottom is maintained for a predetermined duration, which duration depends on the speed displacement of the container in conjunction with the length of the path traveled by the bottom within the liquid. It thus becomes possible to ensure rapid and efficient cooling of the bottoms of the containers, and thus to rapidly freeze the shape and the structural state of said bottoms, thanks to the possibility of a supply of coolant in a quantity and with a efficiency that it was not possible to obtain with the means currently used (gas blowing or spraying of a liquid), with this very important additional advantage of a possibility of industrial implementation in manufacturing facilities. high rate containers.

According to a second of its aspects, the invention also proposes an installation for applying to the parade a liquid on the bottom of at least one container of thermoplastic material driven in displacement so that its bottom follows a pre-established trajectory with a substantially constant slope, said installation comprising a reservoir containing said liquid which is disposed under said bottom trajectory, for the implementation of the process which has just been described, characterized in that it comprises:

at least one elongate nozzle which is disposed at or towards one end of the reservoir located under said bottom trajectory and which extends substantially transversely to said bottom trajectory, which nozzle is directed upwards and is inclined towards the center of the reservoir so as to generate a wall or portion of liquid wall capable of causing a rise in the level of the liquid in the tank, and leakage means in said reservoir which are capable of creating a leak of liquid with a flow rate substantially equal to the flow rate of said at least one nozzle,

said bottom trajectory being situated above the tank in such a way that the bottom of said at least one moving vessel is caused to pass through said liquid wall and into the liquid that it retains in the tank.

In a preferred embodiment, the at least one nozzle is inclined at an angle of between about 20 ° and 60 °, preferably about 40 °.

In a possible embodiment, the nozzle is unique and said bottom trajectory is inclined relative to the level of the liquid in the tank. It is then possible for the nozzle to be located at the end of the tank through which the containers approach: the bottom of each container first passes through the wall of liquid propelled by the at least one nozzle and, providing that the trajectory followed by the bottom of the container is ascending, said bottom continues its path in the liquid until it reaches the surface of the liquid. It is also possible for the nozzle to be located at the end of the tank from which the containers move away: by providing that the trajectory followed by the bottom of the container is downward, said bottom is brought to penetrate the surface. liquid in the reservoir and to be moved within it, until it passes through the wall of liquid to exit the reservoir. However, in a preferred embodiment, the installation comprises at least two nozzles located respectively at or towards two opposite ends of the tank, so that said bottom trajectory can be substantially parallel to the level of the liquid in the tank. It is then possible to constitute the means of displacement of the containers in a simpler way, and especially without vertical recoil, compatible with the practice of high speeds.

As necessary to obtain a significant rise in the level of the liquid in the tank, it is possible to ensure that at least one end of the tank is provided with several nozzles arranged one after the other along said path of the tank. background.

In a concrete embodiment that is simple to implement, it can be provided that the leakage means consist of intervals provided on either side of the at least one nozzle, between the latter and the side walls of the tank. . There may be other embodiments of the leakage, by notches adjustable on the side walls, by vertical tubes of the type "too full", etc. Also, it may be advantageous for the installation to include a collection tank which is adapted to receive the liquid escaping from said leak and which is connected to said at least one nozzle for feeding it with recycling. liquid. It is also conceivable that the installation comprises means for regenerating the liquid escaping by said leakage.

An installation according to the invention may in particular find application, although not exclusively, to rapidly change the bottom temperature of at least one container of thermoplastic material, said liquid then being a heat transfer liquid. In particular, such an installation seems to have to find an application particularly advantageous for rapidly cooling the hot bottom of at least one thermoplastic container that leaves a blow molding or stretch-blow mold, said liquid then being a coolant at a temperature lower than that of the constituent thermoplastic material said background. In such an installation, it may be desirable to provide means for regulating the temperature of the liquid for supplying said at least one nozzle. An installation arranged according to the invention for treating a multiplicity of containers driven in displacement one after the other by transfer means may advantageously be implemented in the form of a rotary installation in which the tank is shaped in a circular arc. and wherein said container transfer means comprises a transfer wheel supporting the containers by their neck coaxially with said tank.

The invention will be better understood on reading the following detailed description of certain embodiments given solely by way of non-limiting examples. In this description, reference is made to the accompanying drawings in which:

- Figures IA and IB are very schematic views, respectively side and end, illustrating the main provisions of the method of the invention;

FIGS. 2A, 2B and 2C are very schematic side views illustrating several examples of implementation of the method of the invention, the example of FIG. 2C being preferred;

FIGS. 3A and 3B are very schematic views, respectively from the side and from above, illustrating a preferred example of implementation of the method of the invention;

FIG. 4 very schematically illustrates another example of implementation of the method of the invention;

FIGS. 5A and 5B are very schematic views, respectively from the side and from above, illustrating an interesting variant of the preferred embodiment of the method of the invention illustrated in FIGS. 3A, 3B;

FIGS. 6A and 6B illustrate, respectively in diametral section and in plan view, a preferred embodiment of an installation arranged in the form of a rotating installation and implementing the method of the invention, this installation being shown in a first functional position in Figure 6A; and

- Figure 6C shows, in diametral section similar to Figure 6A, the installation of Figure 6A in another functional position.

Reference will first be made to FIGS. 1A and 1B which very schematically illustrate the main provisions of a method for applying a liquid 3 to the bottom of the vessel 2 on at least one vessel 1, in particular a bottle, thermoplastic material such as PET, which container 1 is driven in displacement so that its bottom 2 follows a trajectory T (shown diagrammatically by the arrow T in FIG IA) preestablished substantially constant slope passing over a tank 4 containing said liquid 3.

According to the invention, the method comprises the following steps: - At or towards at least one end of the tank 4 located under said trajectory T of the bottom 2, a liquid jet 5 is projected upwardly inclined towards an opposite end of the tank 4 and extending substantially transverse to said trajectory T of the bottom 2 (see FIG. 1B) so as to create a wall or portion of liquid wall 6 or liquid wall 6 located at least higher and adapted to hold liquid 3 and to raise the level H of the surface N of the liquid 3 retained inside the tank 4 (or dynamic level) with respect to the level h that the liquid should normally occupy (static level) in relation to the height of the wall or part of the wall 7 the lowest solid bottom bordering the end tank 4 ; a leak F of liquid having a flow rate substantially equal to the flow rate of the liquid introduced by said jet of liquid is created in said reservoir 4; and

the aforesaid trajectory T of the bottom 2 is positioned above the tank 4 in such a way that the bottom 2 of said at least one moving container 1 is caused to pass through said wall or liquid wall and to pass through, for a period of time predetermined, the liquid 3 that it holds in the tank 4.

The jet 5 of liquid can be obtained in various ways, in particular by juxtaposing a multiplicity of individual juxtaposed jets. However, a preferred way is to generate a single jet elongate transverse to the path T, by means of a single slot nozzle 8 extending over all or part of the width of the tank 4; in the example shown in FIG. 1B, the nozzle 8 extends only over part of the width of the tank 4 so that the displacement of the bottom 2 of the container 1 takes place in a relatively liquid mass larger than the displaced liquid mass in order to significantly reduce waves and liquid splashes. Conveniently, the nozzle 8 is structurally associated with the end wall 7 and is located at the upper portion thereof; the end wall 7 of the tank is notched at 9 and the nozzle 8 is housed in said notch 9 being disposed at a height less than that including the side walls 10 of the tank 4.

Preferably, the liquid jet 5 is inclined relative to the horizontal by an angle of between about 20 ° and 60 °, preferably about 40 ° as seen in FIG.

The liquid is fed under pressure from a source S of liquid, in particular by pumping. In the diagrammatic example shown in FIGS. 1A and 1B, the leak F is shown schematically in the form of a pipe 11 opening in the bottom of the tank 4 and connected to a suitable outlet for the liquid thus recovered; in practice, the pipe 11 is connected, directly or indirectly, to the source S for recycling the liquid, as shown in FIGS. 1A, 1B. Other solutions are possible, a preferred embodiment of which will be indicated later.

The process according to the invention as just described makes it possible to produce a wall or part of the end wall of a tank 4 in a liquid form which can therefore be crossed by a bottom 2 of a container 1 , which bottom 2 then continues to be moved within the mass of liquid 3 contained in the tank 4 for a predetermined time to provide the desired result on said bottom 2. In particular, in a preferred application of the invention, the desired result is the cooling of the bottom 2 that comes out hot from a blowing unit, the liquid used can then simply be water at a lower temperature than the bottom 2, this water can optionally be cooled and / or be added any product (eg wetting agent to promote drying) required for facilitate and make more effective bottom treatment 2.

It will be emphasized that the implementation of the method according to the invention facilitates operation and simplifies the installation: the container can be moved on a continuous level trajectory, without the need to provide path deviations first down to immerse the bottom in the liquid contained in the tank, then upwards to get the bottom of the container out of the liquid. The conveying means moving the container are then simplified and it becomes possible to treat the containers displaced one after the other at high speed: the method can therefore be implemented in manufacturing facilities and / or treatment of containers. very high rate currently developed. Practically, several possibilities are possible for moving the containers.

The trajectory T followed by the bottoms 2 of the containers may be inclined relative to the surface N of the liquid contained in the tank 1, ie with respect to the horizontal, so that the tank 1 does not need to be equipped only one end wall 7 arranged at least partly in the form of a liquid wall 6, the other end wall opposite to it being able to remain a solid wall over which the trajectory T passes.

Thus, in FIG. 2A is illustrated very schematically an arrangement in which it is the wall 7th end of entry or arrival which is arranged as explained above according to the invention, while the opposite end wall or outlet end wall 7s is solid and provided with a sufficient height ( for example of the same height as the side walls) to extend above the level N of liquid; in this configuration, the trajectory T of the bottoms 2 is upward so that the bottoms of the containers enter the liquid mass 3 by crossing the liquid wall 6, then pass through a portion of the mass of liquid 3 with a decreasing immersion and on a length L sufficient to provide funds 2 the desired effect, and finally out of the liquid and pass over the wall 7s end of exit. In FIG. 2B is illustrated an inverse arrangement in which it is the outlet end wall 7s which is arranged as explained above according to the invention, while the end-end wall 7 is solid and provided with the same height as the side walls that extend above the N level of liquid; in this configuration, the trajectory T of the bottoms 2 is descending so that the bottoms of the containers pass over the end-of-end wall 7, penetrate into the mass of liquid 3 while crossing the surface of the liquid, and then continue to through a portion of the mass of liquid 3 with increasing immersion and over a length L sufficient to provide funds 2 the desired effect, and finally out of the mass of liquid 3 through the end of the wall 7s which is arranged as described above according to the invention.

However, a preferred embodiment of the method of the invention consists in that, as can be seen in FIG. 2C, the trajectory T followed by the bottoms of the containers is substantially parallel to the surface N of the liquid contained in the reservoir, otherwise is substantially horizontal. It is then necessary that the two end walls, respectively the inlet end wall 7e and the outlet end wall 7s, are arranged as described above in accordance with the invention. In this case, the immersion length L of the bottoms of the containers corresponds to almost the entire distance separating the two liquid walls in the tank 1.

The main provisions of the invention which have just been described may be subject to numerous adaptations according to the requirements required for the applications specifically envisaged. Thus, as shown in FIGS. 3A, 3B, the leakage F of the aforementioned liquid can be carried out in a particularly simple manner. As a non-limiting example of embodiment, on both sides of the nozzle 8 are provided two respective passages 12 which have a section (in particular a width) suitable for allowing the liquid to flow (arrows F) with a substantially equal flow rate. at the flow rate of the nozzle 8. The leakage liquid is collected in a collection tank 13 located for example in the extension of the tank 4, at the front or respectively at the rear thereof. The pumping means P can then be arranged to pump the liquid into the collection tank 13 (which thus plays the role of the above-mentioned source S) which is thus recycled to feed the nozzle 8 again under pressure. A supplement in addition to liquid can be expected to compensate for losses (not shown).

If necessary, it is possible to provide a regulation of at least one characteristic of the In particular, it may be useful to regulate the temperature of the liquid sprayed into the tank 4 via the nozzle 8, in particular for cooling said liquid, and for this purpose means 14 for thermal regulation can be used. placed in a suitable place, for example in the collection bin 13 as shown in FIGS. 3A, 3B or in the nozzle 8.

Where necessary, it can also be provided, either alone or in combination with the preceding arrangement as shown in FIG. 4, that the recovered liquid is treated in any case required by treatment means before being returned to the nozzle 8, for example to regenerate the liquid and restore properties that have been degraded in contact with funds 2 and / or to add an adjuvant such as a wetting agent to facilitate the subsequent drying funds 2.

Optionally, it is possible to ensure that after the application of the liquid 3 on the bottom 2 of the container 1, at least part of the surface of said bottom 2 is dried, so as to avoid or at least limit the dripping of liquid likely to dirty and pollute the installation (not shown) and / or to speed up the availability of the containers for subsequent operations (eg filling).

As necessary, to raise the level N of the liquid 3 in the central zone of the tank 4, it is perfectly possible to envisage using an arrangement of several nozzles 8 arranged one after the other. FIGS. 5A, 5B thus show an arrangement with two successive nozzles 8. All the nozzles 8 can be fed by common pumping means P as shown in FIG. 5A, or each nozzle 8 can be fed independently by individual pumping means so as to allow individual adjustment of the liquid spray pressure.

The process according to the invention can be used in particular to rapidly modify the temperature of the bottom 2 of at least one container 1 of thermoplastic material, for example PET, it being understood that said liquid 3 is a coolant liquid in contact with which said Bottom 2 of the container 1 is maintained for a predetermined period of time suitable for causing the required change in the temperature of the bottom 2 of the container 1.

A particularly interesting application relates to the rapid cooling of the bottom 2 of at least one container 1 of thermoplastic material, in particular PET, which leaves a blow mold or stretch-blow molding, said liquid 3 then being a coolant at a temperature lower than that of said bottom 2 and in contact with which said bottom 2 is maintained for a predetermined time appropriate to cause the required lowering of the temperature of said bottom 2. It thus becomes possible to ensure rapid and efficient cooling of the bottom of the containers, and thus quickly freeze the shape and the structural state of said funds, thanks to the possibility of a supply of cooling fluid in a quantity and with an efficiency that was not possible to obtain with the means currently used (gas blowing or spraying of a liquid), with these very important additional advantages of not contaminating the environment at in the installation and allow an industrial implementation in container manufacturing facilities. In addition, it should be emphasized that the process according to the invention allows an operation suitable for treating a large number of containers traveling at high speed one after the other in the context of large or very large production installations. capacity, which are now required by the operators.

Although the process which has just been described can be implemented by means of an installation of any suitable conformation such as a linear installation, it is however perfectly possible to design a rotary type installation which is capable of insert much more easily in the context of a conventional production facility that commonly uses, for the displacement of the containers, rotary transfer means in particular arranged in the form of transfer wheels.

Referring now to Figures 6A and 6B, an installation, of the carousel type rotating about an axis X, according to the invention is arranged for implementation of the provisions that have just been exposed. This installation comprises a frame 16 in the general shape of substantially discoidal plateau, substantially horizontal and substantially coaxial with the axis X, which is secured to a substantially vertical tubular sleeve 17 which is coaxial with it.

The frame 16 supports, by means 18 of support, the tank 4 which is here substantially circular arc shape disposed coaxially with the axis X. The tank 4 is delimited by a bottom 19, inner arcuate walls 10 and outer and end walls arranged according to the invention. The tank 4 is fixed in rotation.

Arranged coaxially inside the sleeve 17 tubular journallonne between bearings 20 bearings, a shaft 21 driven in rotation and, for this purpose, the lower end 22, projecting under the frame 16, supports a pulley 23 driven by a belt 24 connected to a suitable drive means such as a motor (not shown ).

At its upper end, the shaft 21 supports a discoidal drum 26 which supports, in the vicinity of its periphery, clamp assemblies 27 of substantially radial extent capable of grasping the containers 1 by their neck 28. The clamp assemblies 27 may be arranged in any manner known to those skilled in the art; in particular, the control of opening and closing of the grippers of the gripper assemblies 27 can be ensured by follower cam and roller control means (s) as is well known in the art (a cam 29 and rollers 30 are visible in Figure 6A). The structure thus formed forms a transfer wheel, generally designated R, which is suitable for moving the rotating containers. Under these conditions, the containers 1 scroll one after the other with their funds along a predetermined path T which is substantially in the form of an arc of a predetermined radius that may preferentially coincide with the center line of the reservoir 4, as symbolized by the arrow T in Figure 6B. Thus, in this preferred arrangement, each clamp assembly 27 is substantially vertically aligned with the median circular cylinder of the reservoir 4, represented by the two right and left Y axes in FIGS. 6A and 6B. As shown in FIG. 6B, the installation is also provided

- An input transfer wheel 31 which brings the containers 1 to a loading axis CH where they are respectively and individually gripped by the above-mentioned clamp means 27, and

- An output transfer wheel 32 which grasps the containers 1 one by one when they reach a discharge axis DCH.

As can be seen in FIG. 6B, the tank 4 extends in a circular arc approximately between the downstream end of the input transfer wheel 31 and the upstream end of the output transfer wheel 32, considered in the direction of the arrow T. As an example, each end of the tank 4 is shown with end walls arranged in the conformation described above with reference to Figures 5A, 5B, with two nozzles 8 generating two successive liquid walls 6 and associated with a tray 13 of collection. The operation of the above-described installation is simple. The input transfer wheel 31 brings the containers 1 to the loading axis CH where they are respectively and individually gripped by the gripper means 27. The clamping means 27 then cause the containers 1 to move in a circular manner so that the bottoms 2 of the containers 1 are forced to pass through the liquid walls 6 of the arrival or arrival end wall, and then be driven within of the raised level N liquid mass which is contained in the tank 4. The containers 1 are transported in this position until they reach the opposite end of the tank 4 where the bottoms 2 successively cross the two liquid walls. 6 of the exit end wall. Once reached the right of the unloading axis DCH, the containers 1 are individually gripped by the output transfer wheel 32.

In the configuration just described, the aforementioned drying means could either be disposed between the outlet of the tank 4 and the unloading axis DCH, or be associated with the output transfer wheel 32.

To extend the scope of use of the installation which has just been exposed, it is desirable that it be able to handle containers of various conformations, including various heights. For this purpose, and noting that the reference level for the displacement of the containers is that of the means 27 clamp, it is advantageous to make the tank 4 movable vertically. Many technical solutions are available to the skilled person.

In a simple example of embodiment shown in FIG. 6A, the means 18 for supporting the reservoir 4 are constituted in the form of a support ring 33 supported by two diametrically opposed columns 34 and able to slide vertically with respect to the frame 16. These columns 34 are integral with racks (not visible) housed in respective housings 35 fixed under the frame 16. An actuating shaft 36, of diametric extent, is engaged through said housings 35 and supports, within those here, respective gears (not visible) which mesh with the respective racks. An appropriate manual control (for example crank 37 shown in FIG. 6A) or motorized adjustment makes it possible to adjust the appropriate height of positioning of the tank 4 as a function of the height of the containers 1. Guide means could be provided to guide the columns 34 during of their vertical sliding. In Figure 6A, the reservoir 4 is disposed in an intermediate vertical position to allow the treatment of containers 1 of average height. In FIG. 6C, which shows the same installation, the tank 4 has been raised to a high position to allow the treatment of containers 1 of small height. Containers of great height could be treated by lowering the support means 18 until contact with the base 16.

To fix the ideas, it will be specified that a correct operation of the installation described above for obtaining the desired cooling funds 2 can be obtained with an elevation of the liquid level in the central portion of the reservoir 4 which is between 5 and 40 mm, depending on the shape of the bottoms of the containers to be treated. To allow an adaptation of the installation in relation to various bottom forms, it may be advantageous to provide various adjustment possibilities, in particular as regards the flow rate of the pumping means supplying the nozzles, the inclination of the nozzles, possibly the width of the nozzle projection slot, the width of the return slots or channels, etc. Of course, many variations of embodiment can be introduced, as necessary, in the facilities that have just been exposed, without departing from the scope of the invention defined in the following claims.

Claims

1. Method for applying to the parade a liquid

(3) on the bottom (2) of at least one container (1) of thermoplastic material driven in displacement so that its bottom (2) follows a path (T) preset with a substantially constant slope passing over a tank

(4) containing said liquid (3), characterized

in that at or at least one end of the reservoir (4) situated under said path (T) of the bottom, at least one jet (5) of inclined liquid is projected upwards towards an opposite end of the reservoir (4) and of substantially transverse extent to said path (T) of the bottom (2) so as to create at least one wall or wall portion (6) liquid to retain liquid and raise the level (N) liquid (3) retained inside the tank (4),

in that a liquid leak (F) is created in said reservoir (4) having a flow rate substantially equal to the flow rate of the liquid introduced by said jet (5) of liquid, and

in that the aforesaid trajectory (T) of the bottom (2) is positioned above the tank (4) in such a way that the bottom (2) of the at least one moving container (1) is caused to pass through said at least one wall (6) liquid and through, for a predetermined duration, the liquid (3) that it retains in the reservoir (4).

2. Method according to claim 1, characterized in that the liquid jet (5) is inclined relative to the horizontal by an angle of between approximately 20 ° and 60 °, preferably approximately 40 °.

3. Method according to claim 1 or 2, characterized in that at least one wall (6) is provided at or near one end of the reservoir (4) and in that said at least one vessel (1) is displaced so that said path (T) followed by its bottom (2) is inclined relative to the level (N ) of the liquid retained in the reservoir (4).

4. Method according to claim 1 or 2, characterized in that at least two liquid walls (6) located respectively at or towards two opposite ends of the tank (4) are provided.

5. Method according to claim 4, characterized in that displacing said at least one container (1) so that said trajectory (T) followed by its bottom (2) is substantially parallel to the level (N) of the liquid retained in the tank (4).

6. Method according to any one of claims 1 to 5, characterized in that at least one end of the reservoir (4) is provided several successive liquid walls (6).

7. Method according to any one of claims 1 to 6, characterized in that regulates (at 14) at least one characteristic, in particular the temperature, of the liquid (3) projected by the at least one nozzle (8). ).

8. Method according to any one of claims 1 to 7, characterized in that recovering the liquid escaping by said leakage (F) and in that the recovered liquid is treated (in 15) before being brought back said at least one nozzle (8).

9. Method according to any one of claims 1 to 8, characterized in that after the application of the liquid (3) on the bottom (2) of the container (1), at least partially the surface of said bottom is dried (2).

The process according to any one of claims 1 to 9 for rapidly changing the temperature of the bottom (2) of at least one container (1) of thermoplastic material, characterized in that said liquid (3) is a coolant liquid in contact with which said bottom (2) is maintained for a predetermined period.

11. Method according to any one of claims 1 to 10 for rapidly cooling the bottom (2) of at least one container (1) made of thermoplastic material which leaves a blow molding or stretch-blow mold, characterized in that said liquid (3) is a coolant at a temperature below that of said bottom (2), in contact with which said bottom (2) is maintained for a predetermined period.

12. Installation for applying to the parade a liquid (3) on the bottom (2) of at least one container (1) of thermoplastic material driven in displacement so that its bottom (2) follows a path (T) preset slope substantially constant, said installation comprising a reservoir (4) containing said liquid which is disposed under said trajectory (T) of the bottom (2), for the implementation of the method according to any one of the preceding claims, characterized in that she understands :

at least one elongate nozzle (8) which is disposed at or towards one end of the reservoir (4) situated under said trajectory (T) of the bottom (2) and which extends substantially transversely to said trajectory (T) of the bottom ( 2), which nozzle (8) is directed upwards and is inclined towards the center of the tank (4) so as to generate at least one wall or wall portion (6) which is clean enough to cause a rise in the level (N) liquid (3) in the reservoir (4), and

means (F) for leakage into said reservoir (4) which are suitable for creating a leak of liquid with a flow rate substantially equal to the flow rate of said at least one nozzle (8),

said trajectory (T) of the bottom (2) being situated above the tank (4) so that the bottom (2) of said at least one moving container (1) is made to pass through said at least one wall (6) liquid and in the liquid (3) that it retains in the tank (4).

13. Installation according to claim 12, characterized in that the at least one nozzle (8) is inclined relative to the horizontal by an angle of between about 20 ° and 60 °, in particular about 40 °.

14. Installation according to claim 12 or 13, characterized in that the at least one nozzle (8) is located at or towards one end of the tank (4) and in that said trajectory (T) of the bottom (4) is inclined relative to the level (N) of the liquid in the tank (4).

15. Installation according to claim 12 or 13, characterized in that it comprises at least two nozzles (8) respectively at or towards two opposite ends of the tank (4).

16. Installation according to claim 15, characterized in that said path (T) of the bottom (2) is substantially parallel to the level (N) of the liquid in the tank (4).

17. Installation according to any one of claims 12 to 16, characterized in that at least one end of the tank (4) are provided several nozzles (8) arranged one after the other along said path (T) from the bottom (2).

18. Installation according to any one of claims 12 to 17, characterized in that the leakage means (F) consist of intervals (12) provided of on either side of the at least one nozzle (8) between it and side walls (10) of the tank (4).

19. Installation according to any one of claims 12 to 18, characterized in that it comprises a collection tank (13) which is adapted to receive the liquid escaping from said leak (F) and which is connected to said at least one nozzle (8) for feeding it.

20. Installation according to any one of claims 12 to 19, characterized in that it comprises means (15) for regenerating the liquid escaping by said leak (F).

21. Installation according to any one of claims 12 to 20 for rapidly changing the bottom temperature (2) of at least one container (1) of thermoplastic material, characterized in that said liquid (3) is a heat transfer liquid.

22. Installation according to any one of claims 12 to 21 for rapidly cooling the bottom (2) of at least one hot container (1) of thermoplastic material which leaves a blow mold or stretch blow molding, characterized in that said liquid (3) is a heat-transfer liquid at a temperature lower than that of the thermoplastic material constituting said bottom (2).

23. Installation according to claim 19 and claim 21 or 22, characterized in that it comprises means (14) for regulating the temperature of the liquid (3) for supplying said at least one nozzle (8).

24. Installation according to any one of claims 12 to 23 arranged to treat a multiplicity of containers (1) driven in displacement one after the other by transfer means, characterized in that the reservoir (4) is shaped in a circular arc and in that said means for transferring the containers (1) comprise a supporting wheel (R) supporting the containers (1) by their neck (28) coaxially with said tank (4).